The basidiomycete fungus, Tilletia constitutes the most important group of smuts economically as they infect cereal grains which provide a major portion of the world’s food supply. The teliospores of the smuts which have been studied have a spore wall layer called the partition layer or the striated zone which is very resistant to fixatives and resins used for electron microscopy. We assume that the chemical nature of this wall layer is the primary factor to prevent spore desiccation and to maintain spore viability for many years. Teliospores of Tilletia tritici (Bjerk.) Wint. (formerly T. caries), T. controversa Kühn, T. indica Mitra, and Neovossia horrida (Tak.) Padwick and Khan all have a reticulated exterior spore layer (sheath). Common bunt, Tilletia laevis Kühn (formerly T. foetida) teliospores lack this exterior reticulated layer, but are also resistant to spore desiccation and maintain viability for many years. Therefore, the purpose of this study was to compare the ultrastructural characteristics of the partition layer of T. laevis teliospores with the partition layer of other teliospores of smut fungi which have been studied.